Speech processing unit with priority assigning function to output voices

ABSTRACT

A speech processing unit assigns priority either to voice guidance processing or to speech recognition processing to be carried out previously, when a speech input requesting for the speech recognition processing is accepted while the voice guidance processing is being carried out. It can solve a problem of a conventional speech processing unit in that when a user operates a speech input button requesting for the speech recognition processing, the currently output voice guidance is interrupted, or the voice guidance scheduled to be output is not produced, thereby hindering the user from obtaining truly necessary information.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a speech processing unitinstalled in a navigation system to carry out voice guidance and speechrecognition.

[0003] 2. Description of Related Art

[0004] Some conventional navigation systems can carry out destinationsetting or institution search not only by operating a remote control ormechanical switches like touch switches, but also by means of acceptinga speech input and performing speech recognition.

[0005] For example, Japanese patent application laid-open No.2000-322098 discloses a speech processing unit for a navigation systemthat devises the following method to increase the speech recognitionreliability.

[0006] When a user operates a speech input button to request acceptanceof a speech input, the speech processing unit silences output soundsfrom car audio equipment so that it does not detect its music or thelike as noise.

[0007] With the foregoing configuration, the conventional speechprocessing unit can improve the recognition reliability of the inputvoice at the cost of the output sounds from a peripheral device such asthe audio equipment, when the user operates the speech input button.Accordingly, it has a problem in that the currently output voiceguidance is interrupted, or the voice guidance to be output is notactually output, thereby preventing the user from obtaining trulynecessary information.

SUMMARY OF THE INVENTION

[0008] The present invention is implemented to solve the foregoingproblem. It is therefore an object of the present invention to provide aspeech processing unit capable of providing a user with importantinformation reliably even when the speech input is carried out.

[0009] According to one aspect of the present invention, there isprovided a speech processing unit including a processing controller forassigning priority either to the processing of a voice guidance sectionor to the processing of a speech recognition section to be carried outpreviously, when the speech recognition section accepts the speech inputwhile the voice guidance section is carrying out or scheduling the voiceguidance processing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a block diagram showing a functional configuration of anavigation system to which an embodiment 1 of the speech processing unitin accordance with the present invention is applied;

[0011]FIG. 2 is a block diagram showing a hardware configuration of thenavigation system of FIG. 1;

[0012]FIG. 3 is a flowchart illustrating a speech processing method ofthe embodiment 1 in accordance with the present invention; and

[0013]FIG. 4 is a flowchart illustrating a speech processing method ofan embodiment 2 in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The embodiments in accordance with the invention will now bedescribed with reference to the accompanying drawings.

[0015] Embodiment 1

[0016]FIG. 1 is a block diagram showing a functional configuration of anavigation system to which an embodiment 1 of the speech processing unitin accordance with the present invention is applied. In FIG. 1, thereference numeral 1 designates a map data storage for storing map dataindicating road information about roads for traveling vehicle; and 2designates a voice data storage for storing voice guidance messages fordirecting the travel of the vehicle. The voice guidance messages aredivided into fixed type messages stored in accordance with the types ofthe voice guidance, and word type messages with concrete values such asdistances and place names. Combining the fixed type and word typemessages can produce desired messages.

[0017] The reference numeral 3 designates a current position detectorfor detecting the current position of the vehicle by reading the outputdata of a GPS receiver and various sensors; 4 designates a traffic information receiver for receiving traffic information; 5 designates anoperating section for accepting route setting for a destination andother various operations of a user; 6 designates a route setting sectionfor searching for a route to the destination set by the operatingsection 5; 7 designates a speech input section for inputting user'sspeech; and 8 designates a speech recognition section for carrying outspeech recognition by searching a speech recognition dictionary for theinput speech.

[0018] Incidentally, the speech input section 7 and speech recognitionsection 8 constitute a speech recognition means.

[0019] The reference numeral 9 designates a system controller forgenerating a route guidance image by reading various data, for example,and for generating a voice guidance message for making voice guidancesuitable for the current situation. The system controller 9 controls theentire system, and particularly controls which processing of the voiceoutput controller 12 and speech recognition section 8 is to be assignedpriority when the speech input section 7 accepts a speech input whilethe voice output controller 12 is carrying out voice guidanceprocessing.

[0020] The reference numeral 10 designates a display controller forgenerating display signals for displaying a road map, current positionmark, destination mark and the like under the control of the systemcontroller 9; 11 designates a display section for displaying the roadmap, current position mark, destination mark and the like in response tothe display signals supplied from the display controller 10; 12designates a voice output controller for controlling the output of thespeech under the control of the system controller 9; and 13 designates avoice output section for outputting the voice in response to the controlof the voice output controller 12.

[0021] Incidentally, the system controller 9, voice output controller 12and voice output section 13 constitute a voice guidance means.

[0022]FIG. 2 is a block diagram showing a hardware configuration of thenavigation system of FIG. 1. In FIG. 2, the reference numeral 21designates a DVD-ROM corresponding to the map data storage 1 and voicedata storage 2; 22 designates a DVD-ROM driver for driving the DVD-ROM21; 23 designates a GPS receiver for receiving radio waves from GPSsatellites to detect the current position of the vehicle; 24 designatesa direction sensor for detecting the direction of the vehicle; and 25designates a distance sensor for detecting the distance the vehicletravels. The GPS receiver 23, direction sensor 24 and distance sensor 25corresponds to the current position detector 3.

[0023] The reference numeral 26 designates an FM multiplex receivercorresponding to the traffic information receiver 4; and 27 designates acontrol unit for carrying out various calculations and control of theentire system. The control unit 27 achieves the functions of the systemcontroller 9, route setting section 6, display controller 10, voiceoutput controller 12 and speech recognition section 8 of FIG. 1. Thereference numeral 28 designates a liquid crystal display for displayingthe display data supplied from the control unit 27. It corresponds tothe display section 11. The reference numeral 29 designates a voiceoutput unit for producing the speech. It corresponds to the voice outputsection 13. The reference numeral 30 designates an input switch like aremote control and touch switch for supplying instructions such asinputting a destination and changing the screen of the display section11. The operating section 5 is one of the functions of the input switch30. The reference numeral 31 designates a microphone for the user toinput speech. It corresponds to the speech input section 7.

[0024] The reference numeral 41 designates a central processing unit(CPU) of the control unit 27; 42 designates a ROM; 43 designates a RAM;44 designates a display controller for carrying out display control ofthe liquid crystal display 28; and 45 designates an input/output (I/O)device for carrying out input and output between the control unit 27 andthe outside.

[0025] The reference numeral 51 designates a digital-to-analog converter(D/A converter) for converting a voice guidance message read in the formof digital signal data into an analog signal; 52 designates an amplifierfor amplifying the voice converted into the analog signal; and 53designates a speaker for outputting the amplified voice.

[0026] Next, the operation of the present embodiment 1 will be describedwith reference to FIG. 3, a flowchart illustrating the speech processingof the present embodiment 1 in accordance with the present invention.

[0027] First, the system controller 9 makes a decision as to whether theuser depresses a talk switch or not for making a speech input (stepST1).

[0028] The talk switch is one of the switches of the operating section5, and is depressed when the user inputs speech to notify the system ofthe speech input for the speech recognition.

[0029] Detecting the depression of the talk switch, the systemcontroller 9 makes a decision as to whether the voice output section 13is producing any voice now (step ST2).

[0030] When no speech is being output, the system controller 9 instructsthe speech recognition section 8 to carry out the speech recognitionprocessing. Thus, the speech recognition section 8 carries out thespeech recognition of the input speech of the user supplied from thespeech input section 7 (step ST3).

[0031] On the other hand, when the voice is being produced, the systemcontroller 9 decides the type of the currently output voice (step ST4) .Specifically, it decides the type of the voice guidance to determine theprocessing to which the priority is to be assigned.

[0032] For example, when the voice guidance currently output is amessage about safety such as a curve precaution or deceleration warning(for example, “Curve ahead, reduce the speed”), the system controller 9prevents the speech recognition section 8 from carrying out the speechrecognition processing, thereby continuing the output of the voiceguidance (step ST5). In this case, to notify the user that the speechrecognition processing cannot be performed, the system controller 9sends a command to display the message on the display controller 10(step ST6). Since this type of the voice guidance is very important andessential for the user, it is assigned the highest priority.

[0033] When the type of the voice guidance belongs to the trafficinformation about a traffic congestion and traffic control, and aboutthe toll information of ETC (electronic toll collection), such as“traffic congestion 1 km ahead” and “toll is 1000 yen”, the systemcontroller 9 carries out the following operation. First, it supplies avoice output interruption command to the voice output controller 12 tosuspend the voice guidance currently output (step ST7). Then, it causesthe speech recognition section 8 to carry out the speech recognitionprocessing of the input voice accepted by the speech input section 7(step ST8).

[0034] Subsequently, after the speech recognition processing of theinput voice has been completed, the system controller 9 supplies thevoice output controller 12 with a voice output resume command to outputthe interrupted message again from the beginning (step ST9) .Alternatively, it may be resumed from the interrupted point, or outputafter being edited to a simpler version. Although this type of voiceguidance is necessary for the user, it can be delayed without anyproblem.

[0035] When the type of the voice guidance is a message associated withroute guidance such as “turn right 500 m ahead”, the system controller 9supplies a voice output halting command to the voice output controller12. Thus, the system controller 9 controls such that the currentlyoutput voice guidance is halted (step ST10), and causes the speechrecognition section 8 to carry out the speech recognition processing ofthe input voice accepted by the speech input section 7 (step ST11). Thisis because although this type of voice guidance is necessary for theuser, if its output is delayed, the user may lose the guided locationbecause the guidance includes information about the distance and thelike. In addition, the operation of the talk switch by the user suggeststhat it is reasonable for the system controller 9 to make a decisionthat the user wishes the operation in accordance with the speechrecognition rather than the route guidance by voice.

[0036] When the voice guidance is associated with a reproduced audiooutput such as music, the system controller 9 mutes the audio speaker(when the voice output section 13 shares the function of the audiospeaker, it mutes the voice output section 13) (step ST12). Then, thesystem controller 9 causes the speech recognition section 8 to carry outthe speech recognition processing of the input voice accepted by thespeech input section 7 (step ST13).

[0037] Subsequently, after the speech recognition processing of theinput voice has been completed, the mute of the audio speaker isreleased (step ST14).

[0038] As described above, the present embodiment 1 is configured suchthat when the speech recognition processing is required by the voiceinput while the voice guidance processing is being carried out, one ofthe voice guidance processing and the speech recognition processing isassigned priority to be carried out previously. Accordingly, the presentembodiment 1 offers an advantage of being able to provide importantinformation without fail even when the speech input is carried out.

[0039] Although the present embodiment 1 automatically decides thepriority of the voice guidance processing and speech recognitionprocessing, this is not essential. For example, a configuration is alsopossible in which the user can set the priority freely.

[0040] Embodiment 2

[0041] When the speech recognition processing is required by the speechinput while the voice guidance processing is being carried out, theforegoing embodiment 1 selects the processing that is assigned priorityto be performed previously. This, however, is not essential. Forexample, when the speech recognition processing is required by thespeech input while the voice guidance processing is scheduled to becarried out, the processing that is assigned priority to be carried outpreviously can be selected as shown in FIG. 4.

[0042] This is implemented as follows.

[0043] First, the system controller 9 makes a decision as to whether theuser depresses a talk switch or not for making a speech input (stepST21).

[0044] Detecting the depression of the talk switch, the systemcontroller 9 makes a decision as to whether or not any voice message isscheduled to be output from the voice output section 13 (step ST22) .For example, a decision is made as to whether the voice output section13 is scheduling to produce a voice message within a certain time periodsuch as 15 seconds or 300 milliseconds.

[0045] When no speech is scheduled to be output, the system controller 9instructs the speech recognition section 8 to carry out the speechrecognition processing. Thus, the speech recognition section 8 carriesout the speech recognition of the input voice of the user supplied fromthe speech input section 7 (step ST23).

[0046] On the other hand, when any voice message is scheduled to beoutput, the system controller 9 decides the type of the voice (stepST24). Specifically, it decides the type of the voice guidance todetermine the processing that is given priority.

[0047] For example, when the voice guidance scheduled to be output is amessage about safety such as a curve precaution or deceleration warning(for example, “Curve ahead, reduce the speed”), the system controller 9prevents the speech recognition section 8 from carrying out the speechrecognition processing, and enables the voice guidance to be output(step ST25). In this case, to notify the user that the speechrecognition processing cannot be performed, the system controller 9sends to the display controller 10 a command to display the notification(step ST26).

[0048] When the type of the voice guidance belongs to the trafficinformation about a traffic congestion and traffic control, and aboutthe toll information of ETC, such as “traffic congestion 1 km ahead”,“toll is 1000 yen”, the system controller 9 carries out the followingoperation. First, it supplies a voice output reservation command to thevoice output controller 12 to withhold the voice guidance scheduled tobe output (step ST27) . Then, it causes the speech recognition section 8to carry out the speech recognition processing of the input voiceaccepted by the speech input section 7 (step ST28).

[0049] Subsequently, after the speech recognition processing of theinput voice has been completed, the system controller 9 supplies thevoice output controller 12 with a voice output start command to outputthe reserved message (step ST29).

[0050] When the type of the voice guidance is associated with routeguidance such as “turn right 500 m ahead”, the system controller 9supplies a voice output halting command to the voice output controller12 to halt the voice guidance scheduled to be output (step ST30), andcauses the speech recognition section 8 to carry out the speechrecognition processing of the input voice accepted by the speech inputsection 7 (step ST31). This is because the voice guidance associatedwith the route guidance is usually output several times in accordancewith the distance rather than only once.

[0051] When the voice guidance is associated with a reproduced audiooutput such as music, the system controller 9 mutes the audio speaker(when the voice output section 13 shares the function of the audiospeaker, it mutes the voice output section 13) (step ST32). Then, thesystem controller 9 causes the speech recognition section 8 to carry outthe speech recognition processing of the input voice accepted by thespeech input section 7 (step ST33).

[0052] Subsequently, after the speech recognition processing of theinput voice has been completed, the mute of the audio speaker isreleased (step ST34).

[0053] As described above, the present embodiment 2 is configured suchthat when the speech recognition processing is required by the speechinput while the voice guidance processing is scheduled to be carriedout, one of the voice guidance processing and the speech recognitionprocessing is assigned priority to be carried out previously.Accordingly, the present embodiment 2 offers an advantage of being ableto provide important information without fail even when the speech inputis carried out.

[0054] Although the present embodiment 2 automatically decides thepriority of the voice guidance processing and speech. recognitionprocessing, this is not essential. For example, a configuration is alsopossible in which the user can set the priority freely.

What is claimed is:
 1. A speech processing unit comprising: voiceguidance means for carrying out voice guidance processing in response toconditions; speech recognition means for carrying out speech recognitionprocessing by accepting a speech input; and processing control means forassigning priority to one of processing of said voice guidance means andprocessing of said speech recognition means to be carried outpreviously, when said speech recognition means accepts the speech inputwhile said voice guidance means is carrying out or scheduling the voiceguidance processing.
 2. The speech processing unit according to claim 1,wherein said processing control means decides the processing to becarried out previously considering a type of the voice guidance.
 3. Thespeech processing unit according to claim 2, wherein if the voiceguidance is associated with safety precautions when said speechrecognition means accepts the speech input while said voice guidancemeans is carrying out the voice guidance processing, said processingcontrol means has the voice guidance processing continued and the speechrecognition processing canceled.
 4. The speech processing unit accordingto claim 2, wherein if the voice guidance is associated with one oftraffic information and toll information when said speech recognitionmeans accepts the speech input while said voice guidance means iscarrying out the voice guidance processing, said processing controlmeans has the voice guidance processing suspended for a time and thespeech recognition processing carried out.
 5. The speech processing unitaccording to claim 2, wherein if the voice guidance is associated withroute guidance when said speech recognition means accepts the speechinput while said voice guidance means is carrying out the voice guidanceprocessing, said processing control means has the voice guidanceprocessing halted and the speech recognition processing carried out. 6.The speech processing unit according to claim 2, wherein if the voicesaid voice guidance means outputs is reproduced audio output when saidspeech recognition means accepts the speech input while said voiceguidance means is carrying out the voice guidance processing, saidprocessing control means has an audio speaker muted and the speechrecognition processing carried out.
 7. The speech processing unitaccording to claim 2, wherein if the voice guidance is associated withsafety precautions when said speech recognition means accepts the speechinput while said voice guidance means is scheduling to carry out thevoice guidance processing, said processing control means has the speechrecognition processing canceled.
 8. The speech processing unit accordingto claim 2, wherein if the voice guidance is associated with one oftraffic information and toll information when said speech recognitionmeans accepts the speech input while said voice guidance means isscheduling to carry out the voice guidance processing, said processingcontrol means has the voice guidance processing postponed and the speechrecognition processing carried out.
 9. The speech processing unitaccording to claim 2, wherein if the voice guidance is associated withroute guidance when said speech recognition means accepts the speechinput while said voice guidance means is scheduling to carry out thevoice guidance processing, said processing control means has the voiceguidance processing halted and the speech recognition processing carriedout.
 10. The speech processing unit according to claim 2, wherein if thevoice said voice guidance means outputs is reproduced audio output whensaid speech recognition means accepts the speech input while said voiceguidance means is scheduling to carry out the voice guidance processing,said processing control means has an audio speaker muted and the speechrecognition processing carried out.